Fuel injectors are typically used with internal combustion engines to spray a combustible fuel into a combustion chamber to mix with charge air brought in through an intake passage. There are a number of issues associated with typical injector designs. One is that the fuel sprayed into the chamber may hit the wall of the combustion chamber. This may be due to spray penetration that is too long. In addition, there may be poor air fuel mixing.
U.S. Pat. No. 6,029,913 discloses a swirl tip injector nozzle encompassing a plurality of curvilinear spray holes resulting in fuel flowing through a tangential flow path within the spray hole and thus rapid spreading and breakup of the fuel spray upon exiting the spray hole.
The inventors herein have recognized a number of shortcomings with this approach. For example, this approach does not appear to have reliable control and/or repeatability of the spray pattern from one combustion event to the next. The swirl tip injector nozzle appears to spin in an uncontrolled way to an unpredictable orientation. Accordingly, the orientation of the injection spray nozzle(s) at the start of a second combustion event may be different than for the first event, and so on for subsequent events.
Further, with this approach, no axial movement of the nozzles is contemplated. Accordingly the spray pattern contemplated or made possible with U.S. Pat. No. 6,029,913 is limited.
The present disclosure provides a fuel injector and fuel injector arrangement wherein the fuel nozzle movement for a second and subsequent combustion event may be reliably repeated.
And, the present disclosure provides a fuel injector and fuel injector arrangement and method wherein the fuel nozzle movement may be in one or both of a rotating direction and axial direction. In this way, a fuel injection spray pattern, once determined to meet predetermined criteria, may be reliably repeated for substantially all combustion events. Further, a wider range of possible spay patterns may be possible. For example, without limitation, a circular pattern or a spiral pattern.
Embodiments in accordance with the present disclosure may provide a fuel injector including a nozzle body having one or more nozzles. Each may be capable of spraying a fuel from a respective spray position. The nozzle body may be movable to change the spray position from a first position to a second position. An injector needle may be configured for axial movement relative to the nozzle body from an engaged position, to prevent flow through the one or more nozzles, to a disengaged position to allow flow through the one or more nozzles. The movement of the one or more nozzles from the first position to the second position and then back to the first position may substantially correspond with, and/or may be substantially be determined by, the relative axial movement between the injector needle and the nozzle body from the engaged position to the disengaged position and then back to the engaged position. In this way fuel is less likely to hit the chamber wall, and/or better air fuel mixture may occur.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.